These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Interleukins 4 and 13 increase intestinal epithelial permeability by a phosphatidylinositol 3-kinase pathway. Lack of evidence for STAT 6 involvement.
    Author: Ceponis PJ, Botelho F, Richards CD, McKay DM.
    Journal: J Biol Chem; 2000 Sep 15; 275(37):29132-7. PubMed ID: 10871612.
    Abstract:
    Interleukins 4 and 13 can affect their target cells by activation of signal transducer and activator of transcription 6 (STAT 6) or phosphatidylinositol 3-kinase (PI3K). We examined the signal transduction events involved in IL-4 and IL-13 regulation of epithelial paracellular permeability using T84 cells, a model human colonic epithelium. T84 cells treated with IL-4 or IL-13 displayed virtually identical dose- and time-dependent STAT 6 activation as assessed by electrophoretic mobility shift assay (EMSA) and decreases in transepithelial resistance (TER). STAT 6 DNA binding activity was maximal in nuclear extracts 30 min after exposure to IL-4 or IL-13, and TER was maximally reduced by 24 h post-treatment. Pretreatment of epithelia with transcription factor decoys (phosphorothioated DNA oligonucleotides containing the STAT 6 binding site) dramatically reduced STAT 6 activation as detected by EMSA, but did not attenuate the TER reduction by IL-4 or IL-13. In contrast, although the PI3K inhibitors wortmannin and LY294002 did not affect IL-4 or IL-13 STAT 6 activation, they significantly inhibited the ability of either cytokine to lower TER. Thus, we provide evidence for PI3K as the major proximal signaling event in IL-4 and IL-13 regulation of TER and speculate that pharmacological targeting of enterocytic PI3K activity may represent a means to manipulate epithelial permeability.
    [Abstract] [Full Text] [Related] [New Search]